Two-flavor mixture of a few fermions of different mass in a one-dimensional harmonic trap

TL;DR

This paper investigates how a mass difference between two fermionic species in a one-dimensional harmonic trap causes phase separation, demonstrating the robustness of this separation against thermal interactions through exact diagonalization.

Contribution

It provides a detailed analysis of mass-induced phase separation in a two-flavor fermionic system using exact diagonalization, highlighting a novel separation mechanism.

Findings

Mass difference induces phase separation regardless of particle number.

Separation mechanism is explained phenomenologically and confirmed via ground-state analysis.

Separation remains stable under thermal environmental interactions.

Abstract

A system of two species of fermions of different mass confined in a one-dimensional harmonic trap is studied with an exact diagonalization approach. It is shown independently on the number of particles that a mass difference between fermionic species induces a separation in the lighter flavor system. The mechanism of emerging of separated phases is explained phenomenologically and confirmed with the help of a direct inspection of the ground-state of the system. Finally, it is shown that the separation driven by a mass difference, in contrast to the separation induced by a difference of populations, is robust to the interactions with thermal environment.